Internal-combustion engine



F. SCHWARZ M mh 24, 1931.

INTERNAL COMBUSTION ENGINE Filed Jan. 2, 1929 #9.1

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Patented Mar. 2.4, 1931 FRIEDRICH SCHWARZ, or HAMBURGQGERMANY INTERNAL-COMBUSTION ENGINE Application filed January 2,

The present invention relates to an internal combustion engine with a stepped piston. According to the invention the engine is intended to be used at high speeds and hence Y the piston must be relieved ot lateral pressures due to the connecting rod. For this purpose the stepped-piston is guided during its entire stroke either externally, by means of slippers, or internally, in that it slides over an inner cylinder projecting from the crankv case into the piston and sealed therefrom.

The invention is shown by way of example in the accompanying drawings in two constructional forms.

Fig. l is a vertical sectional view of the engine.

Figs. 2 and 3 are similar views showing modiiied forms. A

Fig. 4f is an elevation of the stepped-piston. The connecting rod (l is pivotally mounted in the piston f at a, and is articulated in known manner to the crank, b, 0.

In Fig. l a guide is provided in that a gliding member o in which the gudgeon pin a is received and which projects from the bottom of the piston into the inner cylinder Z1 and is guided therein, is made of such a length that it remains during the whole stroke within the inner cylinder Z1. g is the step piston, which together with the cylinder Z1 forms the lower combustion chamber. The inner surface of the cylinder Z1 serves as a gliding path ior the guide piece 0.

According to Figs. 2 and 3 the piston f is guided by means of its upper part in the cylinder e, whereas its lower part glides in an enlarged part of the cylinder h, wherein the step piston g works. The sealing is eiffected by means of rings which are let into the cylinder h. The step gis at the same time formed with slippers 'm and takes up the travelling pressure originating trom the connecting rod d. By means of the step-piston g, the piston f and the external cylinder h, the annular combustion chamber on one side, and by reason oi the piston cover and the cylinder e the combustion chamber on the other side is Jtormed.

The cylinder h may according to Fig. 3,

. the stroke.

1929, Serial No. 329,820, and. in Great Britain November 21, 1928.

beprolonged intozthe crank-case so a-stoy form a cylinder Z so that the piston is suihcientl-y l guided even at its lower dead point, it being possibleto locate the packing rings k on .the

. l J5 A Itis now intended to illustrate the working of the machine according to- Fig.- l. In the position shown thestepped piston f, lg has completed the compression stroke .and

the expansion stroke is aboutl tovbegin.V The f 30 vignition of the working medium in the cylin-4 .der e 1s eiiectedV orinstance, by means of spark plugs. The stepped piston f," g-slides vby reason of the explosion into its second position. Duringv this, stroke the inlet and exhaust valves 'p andV gare closed because v the explosionl takes place in the cyl-indere, but in the cylinder- -h compression takes place. At the end of the period. of the explosion that creates the useful workin the cyl- V2.0 inderfe and also offthe compression period inthe cylinder h, the valvejoY is opened, whereas .the valve g remains closed.y 'As the piston Vreturns to itsstartin'g or i-nitial position the exhaust period takes place inthe cylinder e and the 4explosion period inthe cylinder h. f Thereafter a second stroke cycle .takesplace which produces the suction stroke in the cylinder e, but the exhaust in the cylfinder 7L. Forthis purpose thetwo valves 80 p and g vhave been openedr at the change of When the stroke again reverses, which again'y causes 'the piston to rise, the compression is eiiected in the, cylinderfe and the suction in the cylinderv h, the valve 29 55 being closed,and`the kvalve* -l opened. In thisrnannerv the :operation continues as a four stroke cycle. y l If it is intended to apply the device to two strokev cycle engines, the operations in the cylinders must be so adjusted, that each stroke isa working stroke. The exhaust, suction and compression periods' (scavenging and charging during the explosion stroke in the cylinder e, and during'the explosion stroke occurring during the return stroke of the lpiston in the cylinder h. In this case the'cylinders are provided with scavenging and charging i, 1700 periods) then take place A,g5

ports, which are covered and uncovered by the stepped piston.

aving novv particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is l. An internal combustion engine including a stepped piston and a main cylinder for d Y cooperation with the main portion of the stepped piston, an outer cylinder forcooperation With the stepped portion Vof the piston, and a guide arranged in axial alignment With the main cylinder and of less external diameter than that of the main upper end of the guide extending Within the main cylinder and providing with such main cylinder a guide for the main portion ofthe piston in all movements thereof, a projection rigid With the main portion of the piston and slidably cooperating with the interior of said guide in all positions of the main piston, and a connecting rod secured to and depending from said projection.

n internal combustion engine including a stepped piston, a main cylinder for cooperation With the main portion of the vso stepped piston, an outer cylinder for cooperation With the stepped portion of the piston, a guide arranged in axial alignment with the main cylinder, a projection rigid -vvith the main portion of the stepped piston and slidably cooperating With the interior of the guide 'in Vall operative movements of the stepped piston.

, An internal combustion engine including an integral piston presenting a main piston and an outer stepped piston, a main cylinderin which'the main piston operates, an outer cylinder in Which the stepped piston operates, a guide arranged'inwardly of the outer cylinderand in axial alignment With both the main and outer cylinders, a projection rigid with the main piston and extendc v Y ing below the plane of the main and stepped pistons, said projection cooperating-With the interior ofthe guide and serving through such cooperation as a continuous'guiding element for both the main piston and stepped piston throughout the' full'operative movement of each.

In testimony whereof I affix my signature.

FRIEDRICH SCHWARZ.

cylinder, the Y 

